This article is more than 5 years old. Information may no longer be current.
Lyme disease incidence 10 times higher than reported cases
Click Here to Manage Email Alerts
The CDC has estimated that approximately 300,000 Americans are diagnosed with Lyme disease each year, 10 times the number of cases that are reported annually to the CDC, according to preliminary numbers presented at the 2013 International Conference on Lyme Borreliosis and Other Tick-Borne Diseases.
The estimation is based on three CDC studies that use different methods. In one study, researchers analyzed medical claims information of 22 million insured people for 6 years. In the second study, researchers surveyed clinical laboratories, and the third study included self-reported Lyme disease from a survey given to the general public.
Lyme disease is the most commonly reported tick-borne illness, with more than 30,000 cases reported to the CDC each year, according to a CDC press release. The estimate found in these studies is approximately 10 times higher than the yearly reported number.
“We know that routine surveillance only gives us part of the picture, and that the true number of illnesses is much greater,” Paul Mead, MD, MPH, chief of epidemiology and surveillance for CDC’s Lyme disease program, said in the press release. “This new preliminary estimate confirms that Lyme disease is a tremendous public health problem in the United States, and clearly highlights the urgent need for prevention.”
CDC is continuing to analyze the data from the three studies and is working to identify new methods to kill ticks and prevent illness.
Lyle R. Petersen
“We know people can prevent tick bites through steps like using repellents and tick checks,” Lyle R. Petersen, MD, MPH, director of CDC’s Division of Vector-Borne Diseases and an Infectious Disease News Editorial Board member, said in the press release. “Although these measures are effective, they aren’t fail-proof, and people don’t always use them. We need to move to a broader approach to tick reduction, involving entire communities, to combat this public health problem.”
Perspective
Back to Top
Eugene Shapiro, MD
This report is preliminary and is based on crude estimates. Confirming the accuracy of the estimates will be difficult. It seems likely that this is somewhat of an overestimate because of overreporting, although Lyme disease (like most other infections) is well-recognized as under-reported to CDC. Indeed, the estimate of 10 times the reported number of cases should not be that surprising, since it has always been estimated that the true number of cases of Lyme disease is 4 to 10 times greater than the number of reported cases (most under-reporting likely is erythema migrans). Another striking number is that there were 3.4 million assays done for Lyme disease at six major national laboratories, clearly an underestimate of the number of tests done nationwide. Even if there are 300,000 cases of Lyme disease a year, the vast majority of these patients have erythema migrans, for which serologic testing is not recommended. Consequently there is marked over-testing for Lyme disease. Physicians should remember that doing a serologic test in persons with a low probability of Lyme disease results in poor positive predictive value of the test result.
Click Here to Manage Email Alerts